Process for forming melt-spun carpet fiber

Abstract

A process for preparing melt spun polymeric fiber made from polymerized amide monomers includes the steps of pigmenting the polymer, incorporating within the polymer sufficient SO3H groups or salts thereof to give the polymer a sulphur content of between about 10 and about 160 equivalents per 106 grams polymer and thereafter chemically blocking with a chemical blocking agent a portion of amino end groups present in the sulphonated polymer.

What is claimed is: 
     
       1. A process for forming carpet fiber made from a melt-spun fiber-forming polymer produced from polymerized amide monomers having relatively permanent color yet resisting anionic dyes, said process comprising the steps of: incorporating within the polymer sufficient SO 3  H groups or salts thereof to give the polymer a sulphur content of between about 10 and about 160 equivalents per 10 6  grams polymer, and after said incorporating pigmenting the polymer;   chemically blocking amino end groups present in the sulphonated polymer with an amount of chemical blocking agent sufficient to provide an amino end group content of less than 25 equivalents per 10 6  grams polymer, and   spinning the polymer into carpet fiber.   
     
     
       2. A process for forming a melt-spun polyamide fiber which resists dyeing with anionic dyes comprising the steps of: incorporating within a polyamide sufficient SO 3  H groups or salts thereof to give said polyamide a sulphur content of between about 10 and about 160 equivalents per 10 6  grams polymer;   pigmenting said polyamide;   chemically blocking amino end groups in said sulphonated polyamide, the blocking occurring before or during melt spinning, in an amount sufficient to provide an amino end group content of less than 25 equivalents per 10 6  grams polymer; and   melt spinning said polyamide into fiber.   
     
     
       3. The process of claim 2 wherein said sulphur content of said polyamide is between 60 and 100 equivalents per 10 6  grams polymer. 
     
     
       4. The process of claim 2 wherein the blocking is achieved through reacting the sulphonated polyamide with an end group blocker selected from the group consisting of: lactones of the formula: ##STR6## wherein R 1  is (CH 2 ) n  and n is from 2 to about 8; acetic anhydride;   maleic anhydride;   glutaric anhydride;   benzophenonetetracarboxylic dianhydride;   napthalene tetracarboxylic dianhydride;   benzenetetracarboxylic dianhydride;   cyclobutanetetracarboxylic dianhydride;   succinic anhydride;   benzoic anhydride;   acetic formic anhydride; and   other carboxylic anhydrides of the formula: ##STR7## where R 2  and R 3  are (CH 2 ) n  CH 3 , n=0 to 9 or an aromatic group having up to 9 carbons.   
     
     
       5. The process of claim 4 wherein said chemically blocking provides the polymer with an amino end group equivalence of from about 2 to about 20 equivalents per 10 6  grams polymer. 
     
     
       6. The process of claim 5 wherein said amino group equivalence is from about 4 to about 12 equivalents per 10 6  grams polymer. 
     
     
       7. The process of claim 6 wherein the end group blocker is caprolactone. 
     
     
       8. The process of claim 2 wherein said incorporating is achieved through reacting the amide monomers used in forming the polyamide with at least one sulphonated compound or a salt thereof selected from the group consisting of: 5-sulfoisophathalic acid;   sulphonated styrene;   a sulfoalkyloxycarboxylic or sulfoaryloxycarboxylic acid having the structural formula: ##STR8## where n=1 or 2 and R is an alkyl or aryl radical; a copolymer of vinyl ether and 2-acrylamido-2-methyl propanesulfonic acid;   poly{2-methyl-2((1-oxo-2-propenyl)amino)-1-propanesulfonic acid};   4-chlorocarbonylsulfobenzoic acid anhydride; and   saccharine.